Tiltable log-debarking arm having a swingable self-centering free-end portion



April 15, 19 .1. J. UHLENKOTT 2,

TILTABLE LOG-DEBARKING ARM HAVING A SWINGABLE SELF-CENTERING FREE-END PORTION Filed Sept. 4, 1956 2 Sheets-Sheet l FIG-l FIG-2 mmvrox. I

John J. Uhlenkofl Apnl 15, 1 J. J. UHLENKOTT 2,830,630

v TILTABLE LOG-DEBARKING ARM HAVING A SWINGABLE SELF-CENTERING FREE-END PORTION Filed Sept. 4, 1956 2 Sheets-Sheet 2 FIG-3 INVENTOR; John J.- Uhlenkofl United States Patent TILTABLE LOG-DEBARKING ARM HAVING A SWINGABLE SELF-CENTERING FREE-END POR- TION John J. Uhlenkott, Keuterville, Idaho Application September 4, 1956, Serial No. 607,720

3 Claims. (Cl. 144-208) The present invention is a debarking apparatus and more particularly a debarking head for a debarking machine.

Among the particular objects of the invention are the provision of a debarking head which will operate very rapidly and remove bark cleanly without undue mutilation of the wood; which has a removable and interchangeable debarking blade or member; which will readily accommodate logs having irregularities in peripheral size and shape and also those havingradially extending branch stubs.

These objects and other important objects and features of the present invention will become apparent during the course of the following description when considered in connection with the accompanying drawings wherein one physical embodiment of the invention is exemplified, and wherein like reference numerals are employed to designate corresponding parts.

Referring to the drawing:

Figure 1 is an end elevation of a debarking machine, including the debarking head;

Figure 2 is an enlarged, fragmentary, vertical, lateral cross section of the component parts of the debarking head, certain parts being shown in elevation; and

Figure 3 is a plan view of the debarking head and fragmentary portions of the machine and log.

It is well known in the art to provide a machine structure somewhat similar to a conventional lathe which is adapted to support and axially rotate a log L for the purpose of removing the bark therefrom. The details of such a machine are therefore omitted from this disclosure, but the machine is indicated in its entirety by the numeral 10, and it will be understood it is provided with arbors 12, one at each end of the log adapted to secure the log at its axis, one of which is powered by any convenient means such as by an electric motor to rotate the log.

The machine is provided with a way 14 extending along its full length parallel to the axis of the log L supported and rotated thereby. On this way 14 is slidably supported the debarking head indicated in its entirety by the numeral 16, which constitutes the improvement and subject matter of the present invention.

It will be seen that the head is provided with suitable shape and structure at 18 to co-operate with the way 14 and rigidly support the head for rectilinear movement parallel to the axis of the log L. The head 16 has a base or supporting frame member 20, to which is pivotally supported a manually controllable selectively reversible prime mover 22, here shown to be a hydraulic cylinder having conduits 22' communicating therewith in advance and arrear of a conventional piston 24 to which is secured a piston rod 26.

At its outer end the piston rod 26 is pivotally secured to a laterally extending shaft 28, to which is also pivotally secured a spring-biased compensating or buffer mechanism 30. The buffer mechanism 30 comprises a pair of opposed telescopically related cup-shaped members 2,830,630 Patented Apr. 15, 1958 3232 within which is disposed a compression spring 34. A restricting bolt 36 extends axially through one member 32 with its head outwardly thereof, and is .threadedly engaged in the opposed member 32 to limit the separating movement of said members 32, and yet the bolt 36 is slidable through the first named member 32 so that the cup-shaped members may telescope inwardly and compress the spring 34 upon pressure being applied thereto. At the opposed end the compensator 30 is pivotally secured to a second shaft 38.

Spaced substantially directly below the shaft 28, a rockable support yoke 40 is pivotally secured by means of a shaft 42 to the base or frame member 20 and in vertical elevation is substantially L-shaped. The vertical leg 40a extends upwardly and secures the ends of the shaft 28, and the horizontal leg 40b extends outwardly and supports a horizontally extending shaft 44 to which a debarking arm, indicated in general by the numeral 46, is pivotally secured for vertical tilting movement of its outer free end.

The debarking arm is provided with an upstanding post 48 which is secured to the ends of the shaft 38, and thus it will be seen that the movements of the prime mover 22 will be imparted through the compensator 30 to tilt the debarking arm 46 in a vertical path.

At its lower end, the post 48 is provided with a forwardly extending collar 50 having a vertically disposed axis, and mounting a pivot pin 52, that pivotally supports a swingable outer end portion 54 of the arm 46 for lateral swinging movement of its outer free end.

The collar 50is provided with a fiat outer face at 56 against which a spring-biased follower 58 rests. The follow 58 is biased by a compression spring 60, which is disposed in the outer swingable arm portion 54, so that when the arm moves laterally to either side, as indicated by the broken-line representation of Figure 3, the spring 60 is compressed to a greater degree and its natural tendency to expand effectively seeks to return the arm portion 54 to the position of the full-line representation of Figure 3 midway the lateral sweep of the arm 46.

As shown in Figure 3, when a debarking blade or member 62 contacts a branch stub, as shown at B, it is permitted to shift laterally and move around the stub rather than be caught thereon, and thus will eifectively remove the bark of logs having branch stubs extending radially therefrom.

It will also be noted that the compensator 30 is provided to compensate for circumferential variations in the log L so that as the radius of the log increases and decreases, the debarking blade or member 62 will remain in debarking relationship to the log and will remove the bark from logs having variations in peripheral circumference.

The debarking blade or member 62 is releasably secured by bolts 64 to a vertically tiltable bar 66, pivoted intermediate its length at 68 to the free end of the arm 46 and at its upper end pivotally connected to a manually controlled fluid-operated cylinder 70 by means of which the angle of the blade 62 may be changed as found desirable due to the change in circumference of successive logs.

Without the compensating mechanism 30 and the selfcentering device constituted by the fiat face 56, the follower 58 and compression spring 60, it is not possible to completely remove all of the bark from a log since the shorter radius areas do not receive suflicient pressure from the vertical tilting movement of the arm, and where branch stubs appear, it is necessary to raise the arm 46 over them. However, with the compensating mechanism 30 and the self-centering device, all of the bark may be removed from logs without undue mutilation of the wood beneath the bark.

3 Having thus described my invention, I claim: 1. A log debarker comprising in combination a device for supporting and axially rotating a log; a head on said device; an arm pivoted on said head for tilting move ment of its free outer end in a vertical path; a debarking member on the arm disposed for a selective barkremoving association with such a log; selectively operable power means secured for alternately raisingand lowering the arm to shift said debarking member into and out of debarking association with such a log; a resilient compensator yieldably holding said debarking member against a log being debarked whereby to compensate for irregularities in the circumference of such a log; said arm being pivotally associated with said head for lateral swinging movement-of its free end in a horizontal path; and a self-centering mechanism for yieldably holding said armmidway its field of lateral swing.

2. In a log debarker adapted to support and axially rotate a log; a debarking head disposed relative to a log so supported and rotatedrsaid head having an arm pivoted on a, horizontal axis for vertical tilting movement of its outer free end, and pivoted on a vertical axis for lateral swinging movement of its outer free end; a selfcentering mechanism yieldably maintaining said arm against lateral swinging movement midway its field of sweep; power means including a yieldable buffer for alternately raising and lowering the free end of said arm toward and away from a log supported and rotated by said debarker; and a debarking member on the free end of said arm disposed for selective bark-removing association with such a log.

3. A log-debarking head comprising a supporting frame; a manually controllable selectively reversible prime mover carried by said frame; an arm pivotally supported with respect to said frame and having its outer end movable in a vertical path; said prime mover being operably associated with said arm for imparting selective vertical movement thereof through a yieldable compensator mechanism; said arm being pivotally supported for lateral swinging movement of the free outer end; and a self-centering device for yieldably maintaining said arm disposed midway its field of lateral sweep.

References Cited in the file of this patent UNITED STATES PATENTS Re. 23,765 Pauley et al. Jan. 5, 1954 871,296 Russel et al. Nov. 19, 1907 881,465 Ganes et al. Oct. 11, 1932 2,109,414 Deiters et al. Feb. 22, 1938 2,688,349 Nicholson Sept. 7, 1954 2,795,320 Dillingham June 11, 1957 FOREIGN PATENTS 76,235 Sweden Jan. 10, 1933 921,833 Germany Dec. 30, 1954 

